I. Technical Field
The present invention relates to a refuse/oil removing device for removing refuse and oil contained in drainage from restaurants, as well as a recovery bag for the recovery of such refuse and oil.
II. Description of Related Art
A large amount of refuse having shapes (e.g., food residues, toothpicks and skewers) and oil (sludge such as oil and fat) are mixed in drainage discharged from kitchens for business use such as those in restaurants wherein cooking and washing of tableware are performed frequently. When such refuse and oil flow through a sewer pipe, they adhere to the inner surface of the pipe and coagulate, with a likely consequence that the pipe diameter may be reduced or the pipe may be blocked. There also has been the problem that the environment, including rivers, is badly influenced by outflow of such refuse and oil into a public sewerage.
For preventing the occurrence of the above problem, in restaurants and the like, a grease trap Japanese Patent Laid-Open No. 2002-161577 (pp. 2-3, FIG. 1) for separation of oil and water contained in the drainage is installed on an upstream side of a drain route leading to public sewerage, and refuse and oil are removed from water in the grease trap to prevent the entry of refuse and oil into the public sewerage.
A conventional, known grease trap will now be described with reference to FIG. 10. The grease trap, indicated at 10, is provided in the interior of a body 12 with an internal space for storing drainage discharged from a washing sink in a kitchen of a restaurant. In the interior space, a first tank 16, a second tank 18 and a third tank 20 which are partitioned from one another by means of slidable partition plates 14a and 14b are formed. Drainage from the kitchen washing sink (not shown) is introduced into the first tank 16 through an upstream-side drain passage 22 such as a gutter or a pipe. The first tank 16 and the second tank 18 communicate with each other below the partition plate 14a. Likewise, the second tank 18 and the third tank 20 communicate with each other below the partition plate 14b. An upwardly extending partition plate 24 is provided on the bottom within the second tank 18. With the partition plate 24, drainage introduced from the first tank 16 into the second tank 18 is sure to move once through the upper portion of the second tank 18. As the body 12, which forms the internal space, a wall-like body made of concrete is shown in FIG. 10, but a vessel-like body made of metal or FRP may be adopted.
Refuse having shapes (e.g., food residues, toothpicks and skewers) and oil are contained in the drainage discharged from a washing sink in a restaurant kitchen. A residue basket 26 formed for example by a metallic punch board having a large number of holes about 5 mm in diameter is provided within the first tank 16 so that drainage from an upstream drain passage 22 is introduced into the residue basket 26. The residue basket 26 is for trapping refuse having shapes such as food residues, toothpicks and skewers. Oil not having shape is discharged together with water into the first tank 16 through the holes of the residue basket 26. Since oil adheres to the refuse trapped within the refuse basket 26, a slight amount of oil is trapped within the refuse basket 26. However, most of the oil contained in drainage is discharged through the holes of the residue basket 26 into the first tank 16.
The drainage discharged through the residue basket 26 into the first tank 16 passes below the partition plate 14a and reaches the interior of the second tank 18. The drainage having thus reached the second tank 18 is once moved upward by the partition plate 24. Water and oil are separated from each other in the second tank 18 and the oil stagnates in the upper portion of the second tank 18, while the water stagnates in the lower portion of the same tank. The water thus stagnating in the tank lower portion passes below the partition plate 14b and reaches the third tank 20. A downstream discharge pipe 30 having an opening positioned sufficiently lower than the water level is provided within the third tank 20. The water having reached the third tank 20 is conducted to public sewerage (not shown) through the downstream discharge pipe 30.
Lids 32 with a handle are provided above the first, second and third tanks 16, 18, 20 for taking out the residue basket 26 from the first tank 16 or for washing the partition plates 14a, 14b and those tanks. In the case where the upstream drain passage 22 is a gutter, a lid 34 is provided above the gutter.
In the grease trap 10, refuse having shapes and contained in drainage is trapped by the residue basket 26 provided in the first tank 16. In the second tank 18, oil and water are separated from each other and the oil is allowed to rise and stay in the upper portion of the tank, then the oil thus accumulated in the second tank 18 is removed. In the third tank 20, the water after removal of refuse and oil is stored and is then discharged to a public sewerage or the like through the downstream discharge pipe 30. If the water level in the grease trap 10 with the drainage not flowing into the grease trap 10 is assumed to be a water level 36a, the opening of the downstream discharge pipe 30 is positioned sufficiently lower than the water level 36a. When drainage flows into the grease trap 10 and the water level in the third tank 20 becomes the water level 36b, the water present in the third tank 20 passes through the downstream discharge pipe 30 and is discharged to the public sewerage or the like.